1. Field of the Invention
The present invention relates to a liquid crystal display device, and more particularly, to a liquid crystal display device which is capable of driving a liquid crystal using image signals supplied to two adjacent data lines, and a driving method thereof.
2. Discussion of the Related Art
Generally, a conventional liquid crystal display device is adapted to display an image by adjusting light transmittance of a liquid crystal using an electric field. To this end, the liquid crystal display device comprises a liquid crystal panel including liquid crystal cells arranged in matrix form between two glass substrates and each having a liquid crystal formed between the glass substrates and switching elements for switching signals to be supplied to the liquid crystal cells, respectively, a driving circuit for driving the liquid crystal panel, and a backlight unit for irradiating light to the liquid crystal panel.
Each of the liquid crystal cells of the liquid crystal panel adjusts light transmittance of the liquid crystal based on an electric field formed by a potential difference between an image signal supplied to a corresponding data line and a common voltage applied to an opposite electrode.
However, the conventional liquid crystal display device has problems as follows.
Firstly, a common voltage supply line is required to apply the common voltage to the opposite electrode of each liquid crystal cell, resulting in a reduction in aperture ratio of each liquid crystal cell.
Secondly, because a flicker occurs due to a kickback voltage ΔVp resulting from a parasitic capacitance of each liquid crystal cell, the common voltage must be adjusted to remove the flicker.
Thirdly, a picture quality is degraded due to a horizontal crosstalk resulting from a distortion of the common voltage based on the position of each liquid crystal cell.
Fourthly, a voltage of a direct current (DC) offset component is applied to the liquid crystal due to the kickback voltage, resulting in a deterioration of the liquid crystal.
Fifthly, an afterimage is generated due to a polarity inversion of each liquid crystal cell based on an inversion scheme. That is, in order to reduce the DC offset component and, in turn, the deterioration of the liquid crystal, the conventional liquid crystal display device is driven in the inversion scheme where the polarity is inverted between adjacent liquid crystal cells and on a frame period basis. However, when any one of two polarities of a data voltage is dominantly supplied for a lengthy period of time, an afterimage in which the pattern of the original image appears faintly is generated. This afterimage is called “DC image sticking’ in that a voltage of the same polarity is repetitively charged in the liquid crystal cell.
Sixthly, because the voltage level of an image signal is divided into a positive polarity and a negative polarity on the basis of the common voltage, the image signal has a large swing width based on the polarities, thereby increasing the amount of heat to be generated in a data driving circuit and the amount of current to be consumed therein.